Having problems getting this to work. Fyi, this is a TV with Roku built in. I've tried connecting standard RCA cables from the TV to the amp, did not work. Have also tried using a digital to analog converter using an optical cable from the TV to the converter, and then RCA cables from converter to amp. Still did not work. When disabling the TV speakers and then trying to access the AV icon on Roku, it says no signal found. Has anyone been able to get this to work?